Comparison of three imaging modalities used to evaluate bone healing after tibial tuberosity advancement in cranial cruciate ligament-deficient dogs and comparison of the effect of a gelatinous matrix and a demineralized bone matrix mix on bone healing - a pilot study

Minimally invasive tarsal arthrodesis in 15 dogs

OBJECTIVE

The aim of the present study was to report the outcomes and complications of minimally invasive tarsal arthrodesis (MITA) in dogs.

STUDY DESIGN

Bi-institutional retrospective study.

SAMPLE POPULATION

A total of 15 client-owned dogs.

METHODS

Medical records of dogs undergoing MITA were reviewed to determine outcome and complications. Radiographs were recommended every 4 weeks until clinical union and reviewed to evaluate tibiotarsometatarsal alignment, implant position, subsequent osseous union of the debrided articulations. Time to clinical union and complications were recorded. Clinical union was defined as functional weightbearing limb use with at least 50% of osseous union. Final limb function was defined as full, acceptable, or unacceptable.

RESULTS

Partial tarsal arthrodesis was performed in 10 cases and pantarsal arthrodesis in five cases. Postoperative swelling was minimal. Most complications, 26% major and 40% minor, were implant-related, and explant was required in three dogs. No catastrophic complications occurred. Mean (±sd) radiographic follow-up was 11.4 (±13.1) months Mean (±sd) time to radiographic osseous union was 1.8 (±0.5) months. Mean (±sd) time to clinical union was 3.7 (±0.8) months. Physiological alignment was restored in 12/15 dogs. Complete radiographic union occurred in 46% while in the remaining 54% obtained partial radiographic union, but clinical instability was not observed. Limb function was considered full in six and acceptable in eight dogs. Function was unacceptable in one dog, but the cause was not related to MITA.

CONCLUSION

MITA resulted in restoration of alignment, which was accomplished using MITA techniques. Furthermore, MITA appeared to result in faster healing times and reduced soft tissue complications compared to conventional open approach arthrodesis.

CLINICAL SIGNIFICANCE

MITA may be considered as an option to obtain functional arthrodesis in dogs.

Prevention of Adhesions after Bone Fracture Using a Carboxymethylcellulose and Polyethylene Oxide Composite Gel in Dogs

The formation of adhesions is a common complication following traumatic injuries and surgical procedures, often resulting in pain, stiffness, and loss of function. This study aimed to evaluate the feasibility and safety of using a composite material comprising of carboxymethylcellulose (CMC), polyethylene oxide (PEO), and calcium chloride, for preventing adhesions between muscle and bone during the healing stage, as well as its effect on the bone healing process. Ten healthy purpose-bred laboratory Beagle dogs were randomly subjected to two consecutive operations with a 6-month interval, alternating between left and right forelimbs. On the left forelimb an osteotomy at the ulna was performed, while on the right forelimb the same procedure was supplemented by the application of the anti-adhesion agent in the osteotomy site prior to closure. Clinical, diagnostic imaging, macroscopic, and histological evaluations were performed at various time points. The results showed no significant differences in surgical site perimeter (p = 0.558), lameness (p = 0.227), and radiographic bone healing (p = 0.379) between the two groups. However, the macroscopic (p = 0.006) and histological assessments revealed significantly lower adhesion scores (p = 0.0049) and better healing (p = 0.0102) in the group that received the anti-adhesion agent. These findings suggest that the CMC/PEO composite material is a safe and potentially effective intervention for preventing post-traumatic and post-surgical adhesions in canine patients without compromising bone healing. Further research is warranted to fully characterize the clinical benefits of this approach.

The Use of Stromal Vascular Fraction in Long Bone Defect Healing in Sheep

The objectives of the present study were to evaluate (a) the feasibility of using stromal vascular fraction (SVF) and nanocrystalline hydroxyapatite (nHA) paste in combination for the treatment of segmental bone defect, (b) the quality of the callus produced, (c) the potential improvement of the autograft technique, and (d) the direct comparison of the biomaterial to the use of autogenous cancellous bone. Unilateral, segmental mid-diaphyseal bone defect was created on the right metatarsus of skeletally mature sheep animals (n = 24) under anesthesia (D0). Residual segments were stabilized by stainless-steel plates and appropriate screws. Defects were managed as follows: group A: use of nHA paste to filling, group B: use of autogenous bone graft mixed with nHA bone paste, placed in defect, group C: use of SVF mixed with nHA bone paste injected into defect, group D: use of bone graft and SVF with nHA paste before apposition in bone defect. SVF had been previously isolated from adipose tissue of the animals intra-operatively after digestion with collagenase solution and neutralization. Animals were evaluated clinically and by X-raying and ultrasonographic examination of the defect, at regular intervals, until D90. Ultrasonographic assessment performed along the length of the defect included calculation of the length of the bone defect and assessment of vascularization. SVF was successfully isolated from group C and D animals, with the average yield being 1.77 × 106 cells. The comparison of clinical scores (based on the 'Kaler scale') on each post-operative day indicated significant differences between the four groups on D1 to D30 (p < 0.01); the median clinical score within group A was 2.5 for D1-D30 and 1 for the entire period; respective scores for other groups were 1.5 (p = 0.07) and 0 (p = 0.033). Differences in radiographic assessment scores were significant for scores obtained on D60 (p = 0.049) and D90 (p = 0.006). There was a significant difference between the four groups in the length of the bone defect, as assessed ultrasonographically, for the entire length of the study; median values were 8, 8.5, 6, and 8 mm for groups A, B, C, and D, respectively (p = 0.008). There was a significance in the differences between median scores obtained during the histopathological examination: 2, 11, 13.5, and 12 for group A, B, C, and D (p = 0.022). There was an inverse correlation between the overall scores of histopathological evaluations and the length of the bone defect (observed on D90) (p < 0.0001) and a correlation between the overall scores and the radiographic assessment scores (obtained on D90) (p < 0.0001). This is the first study in which the efficacy of fresh autologous Stromal Vascular Fraction (SVF) from adipose tissue in enhancing bone healing in a long, weight-bearing, diaphyseal bone was evaluated. It is concluded that the lumbosacral region was an attractive site for harvesting adipose tissue, the use of SVF contributed to faster rehabilitation post-operatively, and SVF significantly enhanced bone formation; in general, the results indicated an osteogenic potential of SVF comparable to the gold standard autologous bone graft.

Fuscoside Attenuates Bone Loss in Bone Defects by Regulating The Rankl/Nlrp3/Opg Pathway in Rats

OBJECTIVE

This study evaluated the beneficial effect of fuscoside in the repair of bone defects (BDs) and the possible molecular mechanism thereof.

MATERIALS AND METHODS

In this experimental study, a BD was induced by drilling the rat tibia. The rats were then administered oral fuscoside, at 200 or 300 mg/kg, for 2 weeks. The effect of treatment was assessed based on the bone formation score and on the levels of cytokines and biochemical markers in serum. Tibial expression of the proteins involved in the Rankl/Nlrp3/Opg pathway was determined by quantitative reverse-transcription polymerase chain reaction and western blot assay, and histopathological changes by haematoxylin and eosin and TRAP staining.

RESULTS

In the fuscoside-treated BD rats, the bone formation score improved and inflammatory cytokine levels were reduced. The levels of biochemical markers improved as well, as did the expression of apoptosis proteins. Fuscoside also attenuated the expression of Rankl, Opg, Nlrp3, Runx2, Osterix, and Osteocalcin (Oc) proteins in the tibial tissue of the BD rats and reversed the abnormal histopathological changes.

CONCLUSION

These results suggest that fuscoside improves BD repair by reducing the differentiation of osteoclasts and by regulating the Rankl/Nlrp3/Opg pathway.

Intact Glucocorticoid Receptor Dimerization Is Deleterious in Trauma-Induced Impaired Fracture Healing

Following severe trauma, fracture healing is impaired because of overwhelming systemic and local inflammation. Glucocorticoids (GCs), acting via the glucocorticoid receptor (GR), influence fracture healing by modulating the trauma-induced immune response. GR dimerization-dependent gene regulation is essential for the anti-inflammatory effects of GCs. Therefore, we investigated in a murine trauma model of combined femur fracture and thoracic trauma, whether effective GR dimerization influences the pathomechanisms of trauma-induced compromised fracture healing. To this end, we used mice with decreased GR dimerization ability (GR^dim). The healing process was analyzed by cytokine/chemokine multiplex analysis, flow cytometry, gene-expression analysis, histomorphometry, micro-computed tomography, and biomechanical testing. GR^dim mice did not display a systemic or local hyper-inflammation upon combined fracture and thorax trauma. Strikingly, we discovered that GR^dim mice were protected from fracture healing impairment induced by the additional thorax trauma. Collectively and in contrast to previous studies describing the beneficial effects of intact GR dimerization in inflammatory models, we report here an adverse role of intact GR dimerization in trauma-induced compromised fracture healing.

Single-stage Bilateral Tibial Tuberosity Advancement With Cranial Fixation in an English Bulldog - A Case Report

This article presents a report of single-stage bilateral tibial tuberosity advancement for the treatment of cranial cruciate ligament rupture in an English bulldog. The reconstruction was performed by a new surgical technique involving tibial tuberosity advancement and fixation with two cranially placed lag screws. The patient was able to ambulate normally at a walk without lameness four days postoperatively. Except for bruising of the surgical site, no complications were observed during a six-month follow-up period.